Precision forced alignmentsubtitle generationword-level timingaudio synchronizationtranscript mapping for your audio.
VocaSync delivers true forced alignment—not ASR. Your transcript in, your transcript out with word-level timestamps. 15 languages, SRT/VTT/JSON output, deterministic precision—no hallucinations, no omissions. Accessible through our dashboard or REST API, with workflow paths from synthesis and transcription into alignment.
Core Capabilities
Four core services, one unified API
Generate speech from text, align audio with transcripts, transcribe audio to text, or translate timed subtitles — VocaSync handles each with precision, and bundles them via Workflows when you need them chained.
Speech Synthesis
Text-to-Speech Generation
Convert any text into natural, human-like speech in 57 languages. Choose from 9 distinct AI voices with different tones and personalities. Export to MP3, AAC, OPUS, FLAC, or WAV formats.
Starting at
£0.03 per 1,000 characters
Forced Alignment
Transcript ➔ Precision Timing
Not ASR. Your transcript in = your transcript out. Acoustic alignment gives you word-level timestamps with deterministic precision. No hallucinations, no omissions.
Starting at
£0.02 per minute of audio
Transcription
Audio-to-Text with WhisperX
Convert audio to text using state-of-the-art WhisperX AI. Get segment-level timestamps, review/edit your transcript, then chain into alignment when needed.
Starting at
£0.01 per minute of audio
Translation
Timed Subtitles ➔ Translated
AI translation that preserves timestamps. Cue-by-cue output in SRT, VTT, or JSON. Optional Premium AI Refinement via Claude Sonnet 4.6 for register-faithful tone.
Starting at
£0.080 per 1,000 source chars
Need stages chained? Workflows bundle multiple services with single upfront pricing and refund-on-failure.
Voice Library
9 unique AI voices for every use case
From authoritative to friendly, calm to energetic—find the perfect voice for your content.
Why VocaSync
Built for developers, designed for scale
Developer Experience
Integrate in minutes, not days
Our REST API is designed for simplicity. Just a few lines of code to start generating speech or aligning audio. No complex SDKs to install—use any HTTP client in any language.
- RESTful endpoints with JSON payloads
- Bearer token authentication
- Comprehensive error messages
- OpenAPI 3.0 specification
// Text-to-Speech Synthesis
const response = await fetch("https://api.vocasync.io/v1/synthesis", {
method: "POST",
headers: {
"Authorization": "Bearer voca_your_api_key",
"Content-Type": "application/json"
},
body: JSON.stringify({
text: "Hello, welcome to VocaSync!",
voice: "nova",
format: "mp3"
})
});
const audioBlob = await response.blob();Use Cases
Powering voice across industries
E-Learning
Create accessible educational content with narrated lessons and synchronized captions.
- Course narration
- Multi-language support
- Subtitle generation
Media & Podcasts
Automate transcription and generate voiceovers for podcasts, videos, and broadcasts.
- Podcast intros/outros
- Video narration
- Transcript review + alignment
Accessibility
Make your content accessible with audio versions and accurate captions.
- Screen reader alternatives
- Caption generation
- Audio descriptions
Output Formats
Export your audio in the format that works best for your workflow. From compressed streaming formats to lossless studio quality.
Global Language Support
57 languages for speech synthesis—speak to the world in their native tongue.
15 languages for forced alignment with word-level precision:
Simple, transparent pricing
Only pay for what you use
Speech Synthesis
£0.03 / 1K chars
Forced Alignment
£0.02 / minute
Transcription is pay-as-you-go at £0.01/min (no free tier).
Get Started
Ready to add voice to your app?
Create your free account and get your API key in seconds. Start with our generous free tier—just add a payment method to unlock.